B1304

Code

ALFA ROMEO B — Body

Accessory timer relay circuit

Brand: ALFA ROMEO

Type: B — Body

Views: UK: 4 EN: 8 RU: 6

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Page language: EN

Blown fuse or fusible link feeding the accessory timer relay
Failed accessory timer relay (stuck open/closed or intermittent)
Open, shorted or corroded wiring/connector in relay supply, control or ground circuits
Poor or intermittent ground at relay or BCM
Faulty BCM or module output driver
Aftermarket installations or modifications altering wiring or loading the circuit

Accessories (radio, windows, etc.) do not stay powered for timed interval after ignition off
Accessories remain powered continuously after ignition off (battery drain)
No accessory power when expected
DTC present and stored in BCM when scanned
Intermittent loss of accessory function or erratic behavior

Scan vehicle with an appropriate diagnostic tool and record freeze-frame/live data and any related BCM codes
Visual inspection of relay, fuse box and wiring for corrosion, heat damage, loose pins or water ingress
Verify fuses and fusible links for continuity
Inspect and probe the accessory timer relay connector for correct terminal seating and corrosion
Measure supply voltage at the relay supply terminal (with ignition in appropriate position and key off as required)
Check relay control signal (BCM output) while activating accessory timer function with a scan tool or by cycling ignition; observe for expected switching

Supply voltage at relay feed: ~12 V (approx. 11–14 V) with battery connected
Control/driver signal from BCM: toggles between near 0 V (ground) and supply voltage depending on design when activated; may be switched to ground or +12 V — confirm with OE wiring diagram
Relay coil or driver circuit resistance: typically tens to a few hundred ohms; infinite/open indicates failed coil/driver, near 0 ohms indicates short
Terminal continuity: supply and ground should show low resistance (0.5 V under load) indicates poor connection

Retrieve and record DTC(s) and any related freeze-frame or live data from the BCM with a scan tool.
Visually inspect fuse/relay area and wiring harness for obvious damage, corrosion, water ingress or aftermarket taps.
Verify accessory fuse(s) continuity; replace any blown fuses and retest.
With connector disconnected, inspect relay pins for corrosion and measure coil resistance across the relay coil terminals; if coil is open or shorted, replace relay.
Probe the relay socket: measure battery supply at the supply terminal, measure ground at the ground terminal, and measure the control terminal while commanding the accessory timer with a scan tool or by cycling ignition — compare to expected signal parameters.
Perform a voltage-drop test on supply and ground circuits while operating the accessory timer to reveal high resistance connections.
If wiring and relay check good, swap with a known-good relay (if compatible) to confirm whether relay is at fault.
If fault persists and wiring/relay are good, inspect BCM connector and wiring for damage; consider bench test or replacement of BCM only after confirming wiring and power/grounds.
After repairs, clear DTCs and verify normal function over several ignition cycles and confirm no parasitic drain.

⚠️ Status

Accessory timer relay circuit fault detected (open/short/intermittent).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5 - 2.0 hours

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